Insulated, composite concrete walls formed of a concrete core, covered with sheets of foam plastic material, have been produced by utilizing the sheets to form molds for casting the concrete. That is, a pair of parallel, spaced-apart sheets provide a space or mold into which concrete may be poured. The foam plastic sheets and the concrete form a composite wall when the concrete is cured.
In this type of construction, the sheets are each formed of a number of smaller panels which are interconnected, edge-to-edge, to provide the large sheet. The panels may be interlocked by tongue-and-groove interconnections. In addition, the panels have been interconnected by the use of ties which comprise a pair of spaced apart plates that are connected by strips. Each of the plates is fitted into aligned edge pockets formed in adjacent panel edges to connect the panels. The strips extend across the space between the sheets to connect the sheets.
The ties hold the panels in alignment to form the parallel sheets and hold the sheets in parallelism during the casting of the concrete. Further, the ties serve to reinforce the cast, composite wall structure. An example of this type of construction is illustrated in Canadian Pat. No. 1,187,671, issued May 28, 1985 to Hunter.
The prior ties are of limited strength and are subject to damage by heat due to fires. In addition, the prior ties are inadequate to completely prevent the panels from moving as a result of the substantial hydrostatic forces produced during the pouring of the concrete.
Consequently, the invention herein relates to an improved tie system for aligning and positioning the sheet-forming panels, immobilizing the panels against "floating" or movement due to hydrostatic pressures, and serving to better resist and dissipate any undue heat applied to the wall construction.